Knob retainer clip



p 1957 E. E. AYLOR ETAL 2,805,876

KNOB RETAINER CLIP Filed Aug. 12, 1955 KNSB CiLlP Application August 12, 1955, Serial No. 527,942

4 Claims. (Cl. 287-53) imer, Rock The present invention relates to a device for actuating switches, valves, or the like. More particularly, it relates to improved means including a spring for connecting a knob to an actuating arm.

In electrical ranges, it is the practice to install a box containing a switch within the range and to provide means accessible from the exterior ofthe range for actuating the switch to establish and interrupt a circuit to a heating element. For this purpose, an actuating device is provided including a shaft, one end of which extends into the switch box and the other end of which extends through an opening in the range and is provided with an actuating knob which is accessible from the exterior of the range.

It is the aim of the present invention to provide an actuating device of this type in which improved means is provided for resiliently connecting the shaft to the actuating knob. According to the invention, the actuating knob is provided with an aperture for receiving a spring and the free end portion of the shaft, and a portion of the spring is interconnected with the portion of the shaft that extends into the aperture in such a manner that it prevents movement of the shaft relative to the actuating 'knob during rotative movement of the knob and shaft. The actuating shaft is also constructed in such a manner that the knob and spring may be assembled upon or removed from the shaft by a simple axial movement of the knob and spring.

The invention also contemplates an improved spring having arms for insertion under stress in the aperture of an actuating knob which spring is constructed in such manner that its arms engage the wall surrounding the aperture and are spaced in such relation to each other that when the slotted end portion of a shaft having flat wall portions is inserted in the aperture in the knob, one of the arms of the spring will be received within the slot of the actuating shaft and the other arms of the spring will bear against the fiat wall portions of the actuating shaft.

It is therefore an object of the present invention to provide an improved device for actuating a switch including a shaft, a knob, and a spring, which spring is associated with the knob and the shaft in such manner that when the parts are assembled, the spring maintains the knob in firm engagement with the shaft during rotative movement of the knob and the shaft.

Another object of the invention is to provide an improved device for actuating a switch including an actuating shaft having a slotted end portion of the actuating shaft in such manner that when the parts are assembled, the spring maintains the knob in firm engagement with the shaft during rotative movement of the knob and shaft but is sufiiciently resilient to permit assembly of the knob and spring upon the shaft or the removal of the knob and spring from the shaft by applying a simple axial movement of the knob and the spring toward or away from the shaft.

A further object of the invention is to provide an improved spring for insertion in an aperture in an actuat- 2,8fi5,87% Patented Sept. 10, 1957 hoe ing knob which spring is associated with the knob and the shaft in such manner that when the parts are assembled, the spring serves to maintain the knob in firm engagement with the shaft during rotative movement of the knob and shaft.

Another object of the invention is to provide a spring adapter which is useful in coupling standard types of knobs to odd sized switch shafts.

The invention will be better understood by reference to the accompanying drawing in which:

Fig. 1 is a perspective view of the parts of our improved device and the position they take prior to assembly;

Fig. 2 is a side elevational view of the spring;

Fig. 3 is a plan view of the spring; and

Fig. 4 is a longitudinal section through the knob of Fig. 1.

*While the improved device may be utilized for actuating a shaft for any desirable purpose, such as for controlling valves or the like, as illustrated in the drawings, the device consists of a shaft 1, a spring ,2, and anactuating knob 3, which when assembled, constitutes means for actuating a switch arranged within a box 4 for establishing and interrupting a circuit.

in accordance with the invention, a D-shaped aperture 5 is formed in outwardly extending projection '6 extending from knob 3 which aperture is shaped to receive the spring 2 and the slotted end portion of shaft 1. As shown in the drawings, the wall surrounding theaperture is provided wit fiat wall portions '6 arranged on opposite sides of a groove 7 and the remainder of the aperture is substantially cylindrical or arcuate in shape. The spring 2 is so shaped that it may be inserted under compression in the aperture. The slot 7 is merely for coring purposes and is incidental to the construction shown.

As shown, spring 2 has a substantially U-shaped'portion consisting of arms 8 and 9 formed integral with a connecting portion it! and the opposite end of arm 9 first extends inwardly toward arm 8 as indicated by the numeral 11 and then in a direction rearwardly from arms 8 and 9 and is reversely bent at 12 to provide an arm 13 which extends forwardly at an angle to arms 8 and 9 and terminates in an offset portion 14 that extends toward the connecting portion iii of arms 8 and 9. The groove 7, as stated, is formed between wall portions 6 to facilitate manufacture of the knob 3 which may be formed entirely or partially of a plastic material, and may be omitted in which case a single flat wall portion 6' is provided.

It will be noted that the arms 8 and d are bent slightly so that the ends it and the bent end 12 are slightly higher. This enables the arms to bend to allow for manufacturing tolerances in the shaft and opening of the knob and still assure that a tight fit is effected.

When spring 2 is assembled in place in the aperture, the portion 13 engages the bottom wall of aperture 5, arms 8 and 9 engage the side Wall portions e of the aperture with the connecting portion 1%) extending across the slot 7 at the outer end of aperture 5, and arm 13 which is moved toward arms 8 and 9 during assembly to stress the spring, engages the arcuate-shaped portion of the wall opposite to the slot 7 with its offset portion 14 extending in close proximity to the portion connecting arms 8 and Q.

While the portion of the actuating shaft 1 which extends into an aperture in the switch box may be round, the free end portion of the arm, as shown in Fig. 1, is arcuate or semi-cylindrical in shape and is bifurcated at its free end portion to provide a slot 15 and upper flat wall portions 16. After the spring 2 is inserted in place in the aperture 5 of the knob, the knob 3 is axially applied to shaft 1 in such a manner that the arm 13 of spring 2 shaped wall portion of aperture 5.

e 3 will slide in the slot 15 of the arm, the flat wall portions 16 of the actuating arm will engage arms 8 and 9 respectively, of the spring, tending to straighten out the bend. Thearcuate-shaped portion of the shaft will engage the cylindrical or arcuate-shaped wall portion of the aperture 5. The spring will therefore maintain the shaft 1 in position during the rotative movement of the knob and the shaft to actuate the switch.

'To remove the knob from the shaft, force may be applied to the knob in a direction axially away from the shaft, thus separating the knob and the spring from the shaft. To reassemble the switch, the knob with the spring in place is'moved toward'the shaft in a position in which arm 13 of the spring is again received in the slot 15 of .the shaft at which time the fiat wall portions 16 of the transversely from the ends of said arcuate side wall, a shaft extending into the open end of said recess, said shaft having an arcuate side wall shaped to conform closely to said arcuate side wall of the recess in the knob and flat side wall portions extending transversely from the ends of said arcuate side wall, said shaft having a .slot therein between its fiat side wall portions which extends to its arcuate side wall, and a spring confined bevtween flat side wall portions of the knob recess and the shaft, said spring having a leg extending through said slot in the shaft and bearing against the arcuate side Wall of the knob recess.

2. An actuating device comprising a rotatable knob having a substantially D-shaped axial recess open at one end which is defined by an arcuate side wall and transverse side wall portions extending transversely from the ends of said arcuate side Wall, a substantially D-shaped shaft extending into the open end of said recess, said shaft having an arcuate side wall shaped to conform closely to said arcuate side wall of the knob recess and a fiat side Wall extending between the ends of said arcuate side wall of the shaft and spaced from the fiat side wall portions of the knob recess, said shaft having a slot therein between said arcuate and fiat side walls which extends lengthwise along the shaft, and a spring having a pair of interconnected spaced legs confined between said flat side wall portions of the knob recess and the flat side wall of the shaft at opposite sides of said slot, and said spring having a third leg connected to one of said pair of legs and extending therefrom in said slot along the shaft and bearing against" the arcuate side wall of.

the knob recess. i

3. A spring for coupling an actuating knob to a shaft, said spring having a pair of spaced legs interconnected at one end by an interconnecting segment, said pair of legs and said interconnecting segment lying substantially in a common plane, a third leg connected to the opposite 'end of one of said legs and extending therefrom back between said legs at an acute angle to said common plane and terminating in a free end displaced from said plane.

4. The spring of claim 3, wherein the free end of said third leg is offset from the remainder of the third leg and projects therefrom toward said interconnecting segment.

References Cited in the file of this patent UNITED STATES PATENTS Strange Jan. 31, 1956 

